Die-stock for cutting screws



UNITED SITES P ENT FFICE.

PATRICK MCGLEW, OF WATERFORD, NEW YORK.

DIE-STOCK FOR CUTTING SCREWS.

To all whom t may concern Be it known that I, PATRICK MGGLEW, of Vaterford, in the county of Saratoga and State of New York, have invented certain new and useful Improvements in Screw-Cutting Die-Stocks; and -I do hereby declare that the following is a. full, cle-ar, and eXact description thereof, reference being had to the annexed drawings, making a part of this specification, in which- Figure 1 is a perspective view, embracing the front and top sides of the stock-some parts being broken away; Fig. 2 a plan-the parts above the line y e in Fig. 3 being removed or cut away; Fig. 3, a cross section through the middle of the stock,-the ratchet die-block or holder, being so placed that the line u o in Fig. 2 shall connect the points t and fw; and Fig. 4, a View of a detached cam piece employed in tightening the screw-cutting dies.

The same letters refer to like parts in all the figures.

My invention relates to the improvement of ratchet die-stocks.

The construction and operation of a dietock embracing my improvements is as folows:

A is the body of the stock, having, as usual, a handle, L, L', at each end.

B is the revolving ratchet-block, arranged in the middle of the stock, and in the same plane as the handles, and held in place by the top and bottom journals, a, b, which respectively turn within the sockets in the bottom portion of the stock A, and in the cap-plate F; which plate is fastened to the stock between the abutments J, J', by the screws f, f.

C, D, are the two pawls or clicks, hung to the stock A; by which pawls the ratchet is turned to the right, or to the left, as desired, on vibrating the handles; and by which, the ratchet is also, when required, fastened to the stock so as to move with the handles constantly.

H, H', are the dies, supported by, and {itted to slide upon the bench-like ways 71 7L', and between the sides of the oblong opening therefor in the central part of the ratchet block. The upper faces of the dies H, H', are even with the top side and the lower face of these dies is flush with the bottom side of the ratchet block.

G is a circular plate, fastened by screws g, g, to the top side of the ratchet, so that the dies when in use shall slide accurately bet-Ween this plate and the ways h, 7L'. An opening is made in the middle of the plate G for the passage of the work operated upon.

E, E, are cams, arranged in the ratchet block, within circular recesses I, I, at each end of the opening for the dies. Each of these cams has a journal, v1, on its lower side, turning in a socket, formed in the bottom part of the ratchet block; and also a journal, e, concentric with i, on its upper side, fitted to turn within a socket in the plate G. That part of the cam piece which projects above the plate, G, is made square, so that the cams can be operated by a hand wrench.

In Fig. 2, the red circular lines show the positions of the journals of the cams E; and these cams are of such shape, and are placed in such positions, as shown, that if they are turned in the direction of their arrows, the dies H, H', will be made to gradually approach each other in a powerful manner, and will be securely retained where they are set, in use. The cams E, E, may, with advantage, be placed a little lower in the ratchet block than shown in Fig. 3, so that they shall press more directly against the middle of the dies. I sometimes arrange but one cam E, and then move but one die, yet I prefer two cams, as in the latter case greater movement Lof the dies can be obtained for cutting bolts of many sizes. One half of the ratchet teeth c, c, c, point in the opposite direction to the other half (l, d, cZ-the pawl C, when in action, catching the teeth o, c, and the pawl D, the teeth d, d; that is, B is a two-way ratchet, with each set of teeth extending fully across the face of the ratchet, whereby, in a ratchet of a given thickness stronger teeth can be formed and the two pawls can be made much stouter than when the ratchet is composed of two separate sets of teeth arranged together; and also, both the pawls can be made to operate in the same plane on the ratchet, whereas this is not attainable when the ratchet is composed of two sets of teeth. The stationary ends g, g', of the pawls C, D, instead of being drilled through and hung on pins, as usual, are rounded so as to form partial journals, and placed within sockets in the stock A, and retained by the cap-plate F, as shown; by which mode the pawls are hung with little labor and in the most durable manner.

7c, l, are the usual springs for pressing the pawls into the teeth of the ratchet.

m, n, are thumb-screws, which are screwed through the pawls and against the parts 0, p, of the stock. So that by turning these screws farther through the pawls, the pawls are pressed and held outside the ratchet teeth; but on turning back the thumb screws, the pawls are allowed to be pushed by the springs, 7c, Z, back into the teeth of the ratchet, so as to operate the dies, when in use, as the handles are vibrated., So that if the pawl D is set to act and the pawl C thrown out, as shown in Fig. l, then the ratchet with its dies, will be turned when the handles are vibrated, in the direction of the arrows in that figure. But if D is thrown out and C let in, as shown in Fig. 2, then, on vibrating the handles, the dies will be turned in the direction shown by the arrows in that figure. And if both pawls are let into the teeth, then the dies will vibrate with the handles, and the diestock must then be used in the same manner as ordinary screw-plates or common solid die-stocks.

The advantages secured by the use of a. cheap and durable ratchet die-stock such as I have now described, over stocks wherein the dies do not revolve in the stock, are apparent to experienced machinists, and consist in part in the fact that the workman, after securing his work in the vise, can place himself in the position where he can exert his strength to the best advantage and there stand, working the handles back and forth, until the screw is finished; without being obliged (as he is in cutting screws on large bolts with the common solid die stocks,) to change hands on the handles, nor to twist his body out of balance over his work bench, nor to go around his work as he cuts the screw. Besides, with a ratchet die-stock, a screw can be cut on a bolt where there is not room to revolve the handlesonly room to vibrate them a short distance; and as a two-way ratchet is employed with two adjustable pawls, screws can be cut in this manner in either direction.

I will now point out the improvement which I shall hereinafter claim.

I believe it is new to arrange dies in a two-way circular ratchet operated by two adjustable pawls-not arranged above, nor below the ratchet, but within it-so that the screw threads shall be produced in the same plane as the pawls and handles act on the ratchet. By this improved arrangement of the dies, the stock is rendered more compact and less expensive to construct, and

is less liable to tip to one side and cut imperfect threads in use than when the dies are arranged either above or below the ratchet.

Ratchet drill stocks, auger handles, and wrenches, are in use; and I do not broadly claim attaching screwcutting dies to a two-way or double ratchet moved in either direction as desired by adjustable pawls which are operated by vibrating handles; nor do I broadly claim the employment of a cam or cams for tightening screw-cutting dies; neither do I claim adjusting the pawls by set screws.

I claim as my invention and desire to secure by Letters Patent- The arrangement of one or more' dies within a circular two-way ratchet which is moved by adjustable pawls, as herein described, to secure the-advantages specified;

PATRICK MCGLEW.

Vitnesses A. F. PARK, JOHN MoRAN. 

